Covid-Brain likened to concussion
Well, it seemed inevitable! I finally got COVID….It was mixed emotions. I wasn’t sure if I should be relieved or worried. Fortunately, I had only a mild case and, to be honest, the community segregation around never-ending political and scientific debates over the last few years has felt more detrimental to my overall wellness than the physical symptoms of the SARS-COV 2 virus itself.
On one hand, it does feel relieving to know that I got the dreaded COVID and survived. The world news would certainly have you feel worried that you might not!
Yet, on the other hand, I have a subtle sense of worry, because although humans still cannot agree on the most appropriate action towards the virus, nobody will disagree that we are still in the early stages of learning about post-covid consequences on the body and brain. And I know enough through my own experiences that Sars-CoV-2 does affect the brain. Personally, I have suffered brain fog, headaches, and decreased attention. What’s worse is that I know all too well that these are not trivial symptoms as they closely resemble the many people who I have consulted with a concussion.
Having 7 days of isolation leaves one with plenty of time to read, and so fuelled by worry, I decided to do a dive into some research on “COVID + BRAIN”, in the name of self-preservation and to help those like me.
How does Covid affect the brain?
According to a highly regarded Nature journal, scientists were initially concerned that the virus was readily infecting the brain, but they have since realised that the virus does not easily pass the blood-brain barrier (part of the brain’s defense mechanism). There is some belief that the virus can enter the brain via the lining in the nasal cavity, which is adjacent to the brain, yet it is still debated as to whether this route is the primary cause for brain consequences. (1)
It is thought that the virus causes our body’s immune system cells, called T-cells and macrophages, to go into overdrive, releasing massive amounts of inflammatory cytokines, in what has been labeled a cytokine-storm syndrome.
Studies now suggest that the virus can infect both astrocytes and pericytes – essential supportive cells in the blood vessels and blood-brain-barrier (BBB). Astrocytes and pericytes collectively manage blood flow and defense mechanisms around the brain, as well as determine the metabolic needs of the brain. When these cells are dysfunctional, blood flow to the brain can be restricted and the metabolic needs of the brain are not met, resulting in brain fatigue and the break-down of the all-important BBB.
The virus also has a natural affinity towards the delicate inner-linings of our blood vessels, called endothelial cells. When the virus attacks these cells, the blood vessel breaks down and is more susceptible to vascular consequences. This is another mechanism in which the BBB can become dysfunctional. (2)
So, although the neurons are not infected directly, they are still affected indirectly via the loss of the critical supportive cells around them. Read more about astrocytes and the blood-brain-barrier in the previous article named Blood Brain Barrier.
What is both scary and interesting is that the blood-brain-barrier, and its adjacent astrocytes and pericytes are all thought to be commonly affected by the inflammatory reactions of a head injury, so it is likely that concussion symptoms and covid symptoms could be similar, since their mechanism involve a similar path.
Stroke journal released an article in August 2020, reporting on the emergence of an association between stroke and covid. The article points out that although those with severe respiratory disorders were more likely to have large vessel strokes, even patients with non-respiratory, mild cases of covid were still at risk. (3)
The big question is what is happening to the microvessels of the brain that is going unrecognized? That is, are there subtle changes in the mild cases of Covid patients which are likely to cause long-term problems?
If that was not enough doom, there is also the possibility that your body’s own immune defense mechanism to COVID, in the form of autoantibodies, can cross the BBB and bind to and destroy neurons in the brain. This auto-immune response is still being studied but serves as another potential concern for the brain, post-covid.
More studies….
Another study performed with 300 participants found that there was a suggestion of post-traumatic stress symptoms in hospitalized covid survivors. This study found evidence of enlarged and hyperactive changes in the hippocampus and amygdala regions of the brain, both of which are linked to memory and fear. (4)
Researchers in China in July 2020 found microstructural changes in the brains of 41 out of 60 covid patients. The changes were present in the olfactory, hippocampus, and cingulate regions, correlating with the loss of sense of smell, memory, and emotional regulation, respectively. (5) How long these changes last is a different question altogether. The Royal Australia College of General Practitioners (RACGP) suggests that 11% of covid sufferers will lose smell, on an average of only 5 days. Perhaps the severity of infection will determine the severity and longevity of neurological symptoms. (6)
The University of California San Francisco has released findings of proteins and autoantibodies in the cerebrospinal fluid (the fluid around our brain) of covid patients, indicating inflammatory conditions inside the brain, as well as auto-immune responses. (7)
Yet another study indicated Covid has been implicated with the activation of microglia cells in the hypothalamus, which could potentially cause cognitive dysfunction. (8)
Once again, this is very similar to the sequence of events with brain injury, and in particular, repetitive brain injury.
Stem Cell Reports published an article in February 2021, highlighting the extended neurological symptoms of covid, which included
Vision impairment, encephalitis, psychosis, neurocognitive impairment, dementia, and vascular complications. The report goes on to again suggest that there are two mechanisms by which the brain can be affected. The virus enters the brain environment directly, or the virus creates an indirect immune-system response via the cytokine-storm, BBB breakdown, and consequent disruption of neural circuits. (9)
My personal take on all of this –
From experience, I would predict that there are some people who will be more at risk than others when it comes to indirect damage via the immune system response. This includes those people with pre-existing gut issues, such as “leaky gut”, previous head injuries, previous headaches, and previous mental health disorders. It is also likely that those with metabolic conditions, such as diabetes or thyroid disorders, will also be more likely to suffer post-covid complications. As with concussions, we must remember that the brain relies on a healthy body, and any pre-existing issues have the potential to cause havoc in the delicate operations of the pristine brain environment.
So, what does one do about all this? Personally, I have set myself up with a protocol including lifestyle, diet, and supplements that address the healing of the blood-brain barrier. I have chosen supplements that reduce oxidative stress to the BBB, improve blood flow, activate healing pathways of the endothelial lining, and support the protective pathways of astrocytes and the tight junctions of the BBB. I will also be choosing to exercise gently as I want to minimize oxidative stress during my recovery. I will maximize my sleep, keep stress managed with meditation. I will eat all my veggies and supplement with fibre to get a boost in the production of short-chain-fatty-acids (important immune signaling to the brain). I will stay clear of all alcohol, and I will also be measuring my heart-rate-variability to gain some insight into my nervous system’s recovery trajectory. My brain is my most important asset, so I will do whatever it takes, and I think this goes for everyone!
If anybody is interested in learning more, please feel free to reach out via the contacts page of brainbalanz.com.au.
Regards
Paul Michael
References
- https://www.nature.com/articles/d41586-021-01693-6#:~:text=How%20COVID%2D19%20damages%20the,that%20can%20harm%20brain%20cells.
- https://www.ajnr.org/content/41/9/1632
- https://www.ahajournals.org/doi/10.1161/STROKEAHA.120.031011
- https://www.nature.com/articles/s41380-021-01223-w
- https://www.nature.com/articles/nindia.2020.127.
- https://www1.racgp.org.au/newsgp/clinical/why-do-some-people-infected-with-covid-19-lose-the#:~:text=The%20presence%20of%20these%20variants,an%20average%20of%20five%20days.
- https://www.ucsf.edu/news/2022/01/422156/cerebrospinal-fluid-offers-clues-post-covid-brain-fog
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8250989/
- https://www.cell.com/stem-cell-reports/fulltext/S2213-6711(21)00087-4